1. Field of the Invention
The invention relates to thermochromic indicator materials comprised of polythiophenes.
2. Description of Relevant Art
Polythiophenes are known for their electrically conductive properties. One technique used to study polythiophenes is to analyze associated color changes when the temperature of the polythiophene is varied. Color changes provide insight into the electro-conductive properties of the polymer. There are numerous patent and literature citations which describe this work.
In many instances it is clearly desirable to know when an object or article reaches or has exceeded a specific temperature simply by viewing the object and noting that at least a portion of the object has exhibited a color change. Viewing includes visual observation by an individual or detection of color change by a sensor, which sensor would output a signal to be detected in any suitable manner.
For example, the useful life of many products can become comprised if exposed to temperatures above a pre-determined temperature. Accordingly, a need exists for a thermal indicator that exhibits a controlled color change indicative of when such products, e.g., food and protective fire suits, have been exposed to the pre-determined temperature. The present invention addresses this need.